Traditional methods of analysis of milk lipids and fat content have focused on categorization of these compounds into broad categories of which have nutritional significance. This project will extend these studies to the analysis of specific subclasses of fats and lipids and study their organization and functional properties in milk. Specifically, they will develop protocols for the analysis of total fatty acids, triacylglycerols, (TG) sterols, phospholipids (and fatty acids in these lipid classes), tocopherols, and carotenoids in human milk. They will also develop procedures for the identification in human milk of dietary lipids trans fatty acids, polyunsaturated fatty acids (PUFA), and phytosterols.